A push-pull output circuit is an electronic circuit which includes a pair of active devices such as vacuum tubes, transistors (bipolar, FET) that alternately supply current to, or absorb current from, a connected load.
Push-pull circuits may be included in various types of digital devices and various types of amplifiers. They may include a complementary pair of active devices in an arrangement wherein, for instance, one device sinks current from the load to ground or a negative power supply, and the other device supplies current to the load from a positive power supply.
The output power that can be achieved with a push-pull arrangement is higher than the continuous dissipation rating of either active device and increases the power output for a certain supply voltage. Push-pull amplifiers are also known to reduce distortion (due to cancellation of harmonics of even order).
Push-pull circuits have been used from the early days of electronics, e.g. due to their capability of allowing the use of a loudspeaker in the place of headphones, and continue to be used today e.g. in audio, radio frequency, digital and power electronics systems.
A continuing demand thus exists for improved push-pull circuits.